Chelsea have their chance for revenge on Barcelona. Three years ago they met in the semi-final, and they felt aggrieved to go out. But while Chelsea's progress to the last four was comfortable, until the last six minutes last night, it will not deprive the Barcelona coach Pep Guardiola of too much sleep. Much, much more will be needed in the semis.
With Chelsea taking a 1-0 lead into this game, scoring another goal after 21 minutes and gaining a one-man advantage soon after, there was, until a nervous final six minutes, not too much doubt that they, rather than Benfica, would be hosting the European champions on 18 April and visiting the Nou Camp six days later.
That is not to downplay the achievement. In reaching the Champions League's final four, Chelsea have gone two stages further than any other English team. They have also done it in a difficult season: in fifth place, they are facing their worst Premier League finish under Roman Abramovich.
But that is precisely the problem. This, by any reasonable standard, is the worst Chelsea team in years. While they are clearly less strong, less fit, less sharp and less competitive than they were in April 2009, Barcelona have moved in the opposite direction. And the difficulties Chelsea will have against the Catalans were certainly presaged last night. Against a good Benfica side, but not one from the top category of European teams, they were made to look decidedly backward.
For the 40 minutes in which both teams had 11 men there was only one side playing good football, only one side passing and moving with the imagination and ability which is a necessity at the serious end of Europe's elite competition.
Roberto Di Matteo lined up Jon Obi Mikel and Frank Lampard in front of the back four. His 4-2-3-1 system has worked well at Chelsea so far, producing results that Ramires said had allowed them to rediscover "respect".
But no one would suggest it is as good as their midfield was when Barcelona last came here, back when Chelsea had Michael Ballack, as well as a younger and fitter Michael Essien and Lampard. Last night Benfica just passed round them. Pablo Aimar, the best player on the pitch, dropped behind Oscar Cardozo to create angles and patterns that Chelsea had not even considered.
In the heart of Benfica's midfield, Nemanja Matic, one of the many talented youngsters Chelsea have enthusiastically recruited before going cold on, was a reliable anchor while Axel Witsel strutted briskly around the centre of the park. Either side of Witsel, Nicolas Gaitan and Bruno Cesar shuttled from midfield tidyness to stretching wing-play.
And Chelsea, at times, barely got a touch. Lampard has the intelligence but not the intensity to do that two-man screening job, and Mikel was frequently left with two or three red shirts darting past him and no obvious answer.
Just three minutes in Lampard had to block a Witsel shot on the edge of the box, and soon after it was Terry's turn to stop Aimar in the same fashion. Aimar and Cardozo both found that they had the time and space to drop deep, show for the ball, turn and shoot.
Now imagine if that was Barcelona. No team in the past 20 years has moved the ball or exploited space better than the current European champions. On Tuesday Barcelona, playing 3-3-4, had Sergio Busquets, Xavi and Andres Iniesta in central midfield, with Cesc Fabregas and Lionel Messi drifting in and out of the spaces where conventional teams would have a centre-forward or two. Against this Chelsea midfield it would almost seem like a game between teams from different evolutionary eras.
Of course, there is more than one way to skin a cat. Chelsea could hope to squeeze out a lead in their first leg here, before digging in at the Nou Camp. That is exactly what Jose Mourinho's Internazionale did two years ago, the last time Barcelona lost a semi-final.
But that was one of the great defensive performances of the modern era, and it was not obvious last night that Chelsea could replicate it. Knockout football is not a perfect merit test. Inferior teams, with the help of lucky bounces or decisions, can progress. But if Chelsea thought they were hard done by three years ago, they will need to be repaid in abundance to do better in 2012.